It is known that auxiliary power systems (APU) can by used to reduce or eliminate truck idling by providing a power source other than the main engine which operates the vehicle systems when the truck is not in motion. Hybrid vehicle electric systems can be used to reduce or eliminate engine idling during traffic stops. Regenerative braking can be used to further improve fuel consumption by providing a means of recharging an onboard electric energy storage system. It is also known that a stop-start function can be achieved by utilizing the existing starter of the engine to restart the engine after a stop period, for example, at a stop light.
Representative of the art is U.S. Pat. No. 7,013,646 to Serkh which discloses an auxiliary power system for a motor vehicle primary engine used to drive primary engine accessories when the primary engine is not operating. The system comprises a secondary engine that drives a hydraulic pump. The hydraulic pump is connected to a hydraulic motor. The hydraulic motor is integrated with an accessory belt drive system on a primary engine. The secondary engine drives the ABDS system through the hydraulic pump and hydraulic motor when the primary engine is not operating, thus allowing various primary engine accessories such as air conditioning to be operated while the primary engine is off. A one-way clutch on the primary engine crankshaft prevents the primary engine crankshaft from being turned when the hydraulic motor is driving the belt. A one-way clutch on the hydraulic motor prevents it from being driven when the primary engine is in operation.
What is needed is a vehicle stop/start system integrated with an auxiliary power unit and having regenerative braking.